Stabilo S Move Pen - Scanning at 1p! @ Whsmiths at Meadowhall

Whsmiths at Meadowhall shopping centre are selling these pens (in other colours too) for 1p when I scanned them. They were originally £4.99, reduced to £1.99 instore, according to the label.I am sure this is an error so be quick before it is spotted